On Wed, Aug 26, 2020, 3:31 AM 安超 <anc...@xiaomi.com.invalid> wrote:
> > Hi Greg, Matias, > > The current implementation of Xiaomi’s Bluetooth stack is different with > the current architecture. > HCI transport layer communication will be based on /dev/ttyS* devices > instead of sockets, > > > > The stack module prefers like bluedroid instead of bluez, host/l2cap will > run on userspace, > While I appreciate the need to have a more complete Bluetooth stack working, I am very opposed to this being brought into mainline. It fully bypasses the OS. This would be as if we implemented the full network stack in user space. Doing this also ties us to a critical bit of software that we do not maintain which is also not something I could support. The Bluedroid comparison is a good one, it exists to explicitly work around the Linux stack and further sperate Android from the kernel. This split also let Qualcomm ship there entirely own stack also out of the Kernel. What I will say is that once I implement the HCI socket interface, using the user channel you could easily have zblue run on top of that with no changes to NuttX. Drivers do not have to implement a special tty interface since it can just use the socket interface. This is the whole point of the user channel and how several years ago I added mesh support outside of the Linux kernel. --Brennan
